Hepatitis C virus (HCV) has chronically infected an estimated 170million people worldwide. There are many impediments to the development of an effective vaccine for HCV infection. Dendritic cells (DC) remain the most important antigen-presenting cells for host immune responses, and are capable of either inducing productive immunity or maintaining the state of tolerance to self and non-self antigens. Researchers have recently explored the mechanisms by which DC function is regulated during HCV infection, leading to impaired antiviral T-cell responses and so to persistent viral infection. Recently, DC-based vaccines against HCV have been developed. This review summarizes the current understanding of DC function during HCV infection and explores the prospects of DC-based HCV vaccine. In particular, it describes the biology of DC, the phenotype of DC in HCV-infected patients, the effect of HCV on DC development and function, the studies on new DC-based vaccines against HCV infection, and strategies to improve the efficacy of DC-based vaccines.

No description available.

Current methods for studying RNA binding proteins (RBPs) combine the use of ultraviolet (UV) crosslinking and immunoprecipitation (CLIP) to analyze RNA-protein interactions. An underexplored alternative approach is using site-specific incorporation of photoactivatable non-canonical amino acids (ncAAs) to enhance the crosslinking efficiency of many CLIP protocols. This thesis describes the incorporation of the photo-crosslinking unnatural amino acid p-azido-L-phenylalanine (AzF) into the Hepatitis C Virus (HCV) non-structural protein 3 helicase (NS3h) for photo-crosslinking and in vitro analysis of the potential binding sites found within the HCV RNA genome. From the five potential sites identified from the NS3h crystal structure for AzF incorporation, two sites, E503AzF and Q580AzF, allowed for nucleic acid photo-crosslinking with fluorescently labelled DNA substrates. We further tested if these mutations adversely affected NS3h and binding activity through a molecular beacon helicase assay and fluorescence polarization methods. We found that E503AzF unexpectedly had a faster unwinding rate than wild type (WT) NS3h and managed to have a similar binding affinity to the tested DNA substrate. Finally, we found that there was a 5-fold increase in the photo-crosslinking efficiency of nucleic acids for E503AzF NS3h mutant compared to our WT NS3h at 254 nm UV light. We are currently working on methods for our CLIP-based protocol to ensure quality RNA footprint generation and purification from photo-crosslinked NS3h. Other work contained in this thesis consists of using Prevotella sp. P5-125 Cas13b (PspCas13b), a clustered regularly interspaced short palindromic repeats (CRISPR) RNA-targeting system, which has been previously shown to knockdown viral RNA and mRNA through designable guide CRISPR RNA (crRNA). Here we incorporated the photo-crosslinking ncAA AzF into PspCas13b to irreversibly bind the crRNA in an attempt to enhance knockdown efficiency and longevity of viral and mRNA targets. We were able to design a crRNA that produced significant knockdown targeting the luciferase mRNA of a luciferase rennilla reporter system. When targeting an HCV subgenomic replicon luciferase reporter system, knockdown was not observed. Additionally, the WT PspCas13b had photo-crosslinking to the bound crRNA and requires further optimization for future use.

Hepatitis C virus (HCV) infection is common among injection drug users (IDUs). There is accumulating evidence that circulating microRNAs (miRNAs) are related to HCV infection and disease progression. The present study was undertaken to determine the in vivo impact of heroin use on HCV infection and HCV-related circulating miRNA expression. Using the blood specimens from four groups of study subjects (HCV-infected individuals, heroin users with/without HCV infection, and healthy volunteers), we found that HCV- infected heroin users had significantly higher viral load than HCV-infected non-heroin users (p=0.0004). Measurement of HCV-related circulating miRNAs in plasma showed that miRs-122, 141, 29a, 29b, and 29c were significantly increased in the heroin users with HCV infection, whereas miR-351, an HCV inhibitory miRNA, was significantly decreased in heroin users as compared to control subjects. Further investigation identified a negative correlation between the plasma levels of miR-29 family members and severity of HCV infection based on aspartate aminotransferase to platelet ratio index (APRI). Heroin use and/or HCV infection also dysregulated a panel of plasma miRNAs. Taken together, these data for the first time revealed in vivo evidence that heroin use and/or HCV infection alter circulating miRNAs, which provides a novel mechanism for the impaired innate anti-HCV immunity among IDUs. Recent studies revealed that extracellular miRNAs were able to incorporate into cell-derived exosomes as a method of cell-to-cell interaction. Exosomes are a class of cell-released small vesicles that mediate intercellular communication by delivering functional factors to recipient cells. During HCV infection, the interaction between liver resident macrophages and hepatocytes is important for host defense and viral elimination, triggered by innate immune activation, especially Toll like receptors (TLR). In our study, we explored the role of macrophage-derived exosomes in the transmission of innate immune responses against HCV infection in hepatocytes, and the involvement of exosomal miRNAs in transferring the anti-HCV activities. We reported that upon TLR3 activation, macrophages shed exosomes that were able to attenuate HCV-JFH1 infection in Huh7 cells. We further demonstrated that exosomes from poly I:C treated macrophages were internalized by Huh7 cells, which induced the intercellular anti-HCV responses (type I interferon, interferon stimulated genes, etc.) and thus drastically inhibited HCV infection in Huh7 cells. Moreover, using an in vitro macrophage and Huh7 cell co-culture model, we also found exosomes mediated HCV suppression in Huh7 cells after TLR3 activation. The presence of exosome inhibitor in co-culture compromised the anti-HCV activity by TLR3-activated macrophages. Interestingly, the miRNA-29 family, which was reported to suppress HCV infection, was significantly increased in the macrophage exosomes after TLR3 activation. The inhibition of miRNA-29 partially compromised the anti-HCV activity of TLR3-activated macrophages, indicating the potential involvement of exosomal miRNAs in the transmission of anti-HCV activity from macrophages to Huh7 cells through exosomes. In conclusion, this study proposed an antiviral mechanism of TLR3 activation that involves the intercellular communication between immune cells and hepatic parenchymal cells via exosomes, and exosomal miRNAs. This discovery sheds light on exploiting the therapeutic potential of new drugs against HCV infection. / Pathology

Hepatitis E virus (HEV), the causative agent of hepatitis E, is endemic in many developing countries. However, sporadic cases of acute hepatitis E have also been reported in industrialized countries including the United States. Increasing evidence suggested that hepatitis E is zoonotic. Swine HEV was discovered in 1997 from a pig in the United States and has the ability to cross species barrier and infect humans. There are four major genotypes of HEV worldwide and swine HEV identified to date in different countries belongs to either genotypes 3 or 4. Thus far, genotypes 1 (Asian strains) and 2 (a single Mexican strain) of HEV are exclusively found in humans. To determine if genotypes 1 and 2 of HEV also exist in pigs we tested serum and/or fecal samples for from pigs of different age groups in Thailand, and from pigs 2-4 months-of-age in two states (Sonora, Sinaloa) in Mexico. A universal RT-PCR was first standardized to detect all 4 different genotypes of HEV. Swine HEV RNA was detected from in 10/26 pigs at 2-4 months-of-age but not in pigs of 1-, 6-month old, adult/sow pigs from Thailand. In Mexico, swine HEV RNA was detected in 8 of 125 serum samples, 28 of 92 fecal samples of 2-4 month-old pigs. Antibodies to swine HEV were detected in 101 of 125 (80.8%) Mexican pigs. A total of 44 swine HEV isolates were amplified and sequenced for the ORF2 capsid gene region. Sequence analyses revealed that all the swine HEV isolates identified from pigs in Thailand and Mexico belong to genotype 3. Overall, the Mexican swine HEV isolates shared 89-100% sequence identity to each other, and about 89-92% identity with the prototype genotype 3 US swine HEV. The Thailand swine HEV isolates displayed 97-100% nucleotide sequence identity with each other, and 90-91% identity with the prototype genotype 3 swine HEV. Phylogenic analysis revealed that minor branches do exist among Mexican swine HEV isolates. The results from this study indicated that genotype 1 or 2 swine HEV does not exist in pig from countries where human genotypes 1 and 2 HEVs are prevalent. / Master of Science

Mathematical models have long been used to describe complex biological interactions with the aim of predicting mechanistic interactions hard to distinguish from data. This dissertation uses modeling, mathematical analyses, and data fitting techniques to provide hypotheses on the mechanisms of immune response formation and function. The immune system, comprised of the innate and adaptive immune responses, is responsible for protecting the body against invading pathogens, with disease or vaccine induced immune memory leading to fast responses to subsequent infections. While there is some agreement about the underlying mechanisms of adaptive immune memory, innate immune memory is poorly understood. Stimulation with lipopolysaccharide induces differential phenotypes in innate immune cells depending on the strength of the stimulus, such that a secondary lipopolysaccharide encounter of a constant dose results in either strong or weak inflammatory cytokine expression. We model the biochemical kinetics of three molecules involved in macrophages responses to lipopolysaccharide and find that once a macrophage is programed to show a weak inflammatory response this cannot be reverted. Contrarily, a secondary lipopolysaccharide stimulus of a very high dose or applied prior to waning of the effects of the primary stimulus can induce a phenotype switch in macrophages initially programed to show strong inflammatory responses. Some pathogens, such as the hepatitis B virus, have developed strategies that hinder an efficient innate immune response. Hepatitis B virus infection is a worldwide pandemic with approximately 257 million chronically infected people. One beneficial event in disease progression is the seroclearance of hepatitis B e antigen often in combination with hepatitis B antibody formation. We propose mathematical models of within-host interactions and use them to predict that hepatitis B e antibody formation causes hepatitis B e antigen seroclearance and the subsequent reactivation of cytotoxic T cell immune responses. We use the model to quantify the time between antibody formation and antigen clearance and the average monthly hepatocyte turnover during that time. We further expand the study of hepatitis B infection, by investigating the kinetics of the virus under an experimental drug administered during a clinical trial. Available drugs usually fail to induce hepatitis B s antigen clearance, defined as the functional cure point of chronic hepatitis B infections. Drug therapy clinical trials that combined RNA interference drug ARC-520 with entecavir have shown promising results in reducing hepatitis B s antigen titers. We develop pharmacokinetic-pharmacodynamic models describing the mechanistic interactions of the drugs, hepatitis B virus DNA, and virus proteins. We fit the model to clinical trial data and predict that ARC-520 alone is responsible for the reduction of hepatitis B s and e antigens, while entecavir is the driving force behind viral reduction. This work was supported by Simons Foundation, Grant No. 427115, and National Science Foundation, Grant No. 1813011. / Doctor of Philosophy / Mathematical models have long been used to describe complex biological interactions with the aim of predicting interactions that explain observed data and informing new experiments. This dissertation uses modeling, mathematical analyses, and data fitting techniques to provide hypotheses on the mechanisms of immune response formation and function. The immune system, comprised of the innate and adaptive immune responses, is responsible for protecting the body against invading pathogens, such as viruses, bacteria, or fungi. If an immune response to a secondary pathogen encounter differs from the response when the body first encounters the specific pathogen, this is called immune memory. The mechanisms underlying the memory of immune responses are well understood in the context of adaptive immune responses, but less so for innate immune responses. Stimulation with lipopolysaccharide, a cell wall component of many bacteria, programs innate immune cells, such as macrophages, to be in one of two states, called phenotypes, depending on the strength of the stimulus. Based on their phenotype the macrophages show either a weak or strong inflammatory response upon a secondary lipopolysaccharide encounter of a constant dose. We model the biochemical kinetics of three molecules involved in macrophages responses to lipopolysaccharide. We find that once a macrophage is programed to show a weak inflammatory response this cannot be reverted. Contrarily, a secondary lipopolysaccharide stimulus that is either of a very high dose or applied before the effects of the primary stimulus have waned, can induce a phenotype switch in macrophages initially programed to show strong inflammatory responses. Some pathogens, such as the hepatitis B virus, have developed strategies that hinder an efficient innate immune response. Hepatitis B virus infection is a worldwide pandemic with approximately 257 million chronically infected people. Hepatitis B e antigen is a protein that infected liver cells release into blood and that impairs adaptive immune responses. It is considered a beneficial event in disease progression, and called hepatitis B e antigen clearance, when hepatitis B e antigen becomes indetectable in a patient's blood. We propose mathematical models of interactions between liver cells, the virus, hepatitis B e antigens and hepatitis B e antibodies, which neutralize the antigens. We predict that antibody formation causes antigen clearance and a reactivation of immune responses. We furthermore use the model to quantify the time between antibody formation and antigen clearance and the average number of liver cells killed during that time. We further expand the study of hepatitis B infection, by investigating the kinetics of the virus under an experimental drug administered during a clinical trial. Available drugs rarely induce hepatitis B s antigen clearance, but clinical trials that combined a novel drug, called ARC-520, with the commonly used drug entecavir have shown promising results in reducing hepatitis B s antigen titers in the blood of infected patients. Following the clearance of hepatitis B s antigen, a protein that is released by infected cells and impairs adaptive immunity, the body usually has the capability to control the infection without medication. We develop mathematical models describing the interactions of the drugs, hepatitis B virus, and virus proteins. We fit the model to clinical trial data and predict that ARC-520 alone is responsible for the reduction of hepatitis B s and e antigens, while entecavir is the driving force behind viral reduction.

Student Number : 9906382M MSc (Med) dissertation - Faculty of Health Sciences / The G1862T mutation in the bulge of the RNA encapsidation signal, in the precore region of hepatitis B virus, results in reduced expression of HBeAg and accumulation of the HBeAg precursor in the endoplasmic reticulum (ER)/Golgi apparatus of the cell. This accumulation can disturb the functioning of the ER and lead to the ER stress response that can affect various cellular pathways, in turn affecting cell viability. The aim of this study was to determine whether apoptosis or necrosis occurred when cultured Huh7 cells were transfected with a plasmid expressing the G1862T mutation. Plasmid constructs, with and without the G1862T mutation, were used to transfect cells. To differentiate between necrosis and apoptosis cells were stained with propidium iodide or YO-PRO-1®, respectively. These were analyzed quantitatively using flow cytometry and qualitatively using confocal microscopy. Confocal microscopy, using monoclonal anti- HBe and the Hoechst stain, was performed to ensure that apoptosis was present as a result of the accumulation of the G1862T mutant HBeAg precursor. Caspase profiling was carried out using a fluorogenic-based assay. When cells were transfected with wild-type plasmid, necrosis predominated over apoptosis. Apoptosis predominated when the cells were transfected with the G1862T mutant plasmid. The highest levels of apoptosis occurred at 72 hours post-transfection. Confocal microscopy revealed the co-localization of aggregates of mutant HBeAg precursor with apoptotic nuclei. Transfection with G1862T mutant plasmids resulted in significant differences in the expression of caspase 3, 8, and 9 relative to the wild-type, at 48 and 72 hours post-transfection. The accumulation of the G1862T mutant HBeAg precursor, in the ER/ Golgi compartment, leads to apoptosis and affects the levels of caspase expression.

Chan Ka Ping Sophie. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 140-144). / Abstracts in English and Chinese. / Thesis/Assessment Committee --- p.i / Acknowledgements --- p.ii / Abstract --- p.viii / 摘要 --- p.x / Abbreviations --- p.xi / List of Figures --- p.xii / List of Tables --- p.xiv / Chapter 1 --- Introduction / Chapter 1.1 --- Pathogenesis of HBV Infection --- p.1 / Chapter 1.2 --- Classification and Structure --- p.2 / Chapter 1.3 --- HBV Genome --- p.4 / Chapter 1.4 --- Replication Cycle --- p.7 / Chapter 1.5 --- HBV Genotypes and Nomenclature --- p.9 / Chapter 1.5.1 --- Asian prevalent genotypes --- p.9 / Chapter 1.5.2 --- Numbering system --- p.9 / Chapter 1.6 --- Identification of Markers in HBV Genome for HCC Development --- p.11 / Chapter 1.7 --- Project Objective --- p.13 / Chapter 1.8 --- Promoters of HBV --- p.14 / Chapter 1.8.1 --- Pre-S1 promoter --- p.14 / Chapter 1.8.2 --- X promoter and enhancer I --- p.14 / Chapter 1.8.3 --- Core promoter and enhancer II --- p.15 / Chapter 1.8.4 --- Pair of mutations at BCP --- p.17 / Chapter 2 --- Materials and Methods / Chapter 2.1 --- Construction of pGL3-promoter Plasmids --- p.18 / Chapter 2.1.1 --- Templates selection --- p.18 / Chapter 2.1.2 --- Amplification of promoters --- p.19 / Chapter 2.1.3 --- Cloning into pGL3-basic vector --- p.21 / Chapter 2.1.4 --- Screening and plasmid preparation --- p.21 / Chapter 2.2 --- Construction of Mutant Promoter Clones --- p.23 / Chapter 2.2.1 --- Site-directed mutagenesis --- p.23 / Chapter 2.2.2 --- pPreS 1 /2712C mutant clone --- p.24 / Chapter 2.3 --- Cloning of Full-length HBV Genomes --- p.26 / Chapter 2.3.1 --- Replication-competent HBV clone --- p.26 / Chapter 2.3.2 --- Amplification of full-length HBV genome --- p.28 / Chapter 2.3.3 --- Cloning into pUC19 vector --- p.28 / Chapter 2.3.4 --- Screening for insert and sequence confirmation --- p.29 / Chapter 2.3.5 --- Excision of full-length HBV from plasmid --- p.29 / Chapter 2.4 --- Re-construction into a 1.3-fold HBV Clone --- p.32 / Chapter 2.4.1 --- Cloning of HBV fragment nucleotide 979-2617 (nt 979-2617) --- p.32 / Chapter 2.4.2 --- Screening for insert and sequence confirmation --- p.33 / Chapter 2.4.3 --- Cloning of HBV fragment (nt 905-2000) --- p.33 / Chapter 2.4.4 --- Construction of a 1.3-fold HBV genotype Cs clone --- p.34 / Chapter 2.5 --- Cell Culture --- p.37 / Chapter 2.5.1 --- Cell culture maintenance --- p.37 / Chapter 2.5.2 --- Transient transfection of promoter clones --- p.37 / Chapter 2.5.3 --- Transient transfection of HBV genomes --- p.38 / Chapter 2.6 --- Dual-Luciferase® Reporter Assay System --- p.40 / Chapter 2.6.1 --- Principle of the assay --- p.40 / Chapter 2.6.2 --- Cell harvest --- p.43 / Chapter 2.6.3 --- Luciferase assay --- p.43 / Chapter 2.7 --- Data Analysis --- p.44 / Chapter 2.8 --- Extraction of HBV DNA from Intracellular Cores --- p.45 / Chapter 2.8.1 --- Harvest of intracellular cores --- p.45 / Chapter 2.8.2 --- Phenol/chloroform extraction --- p.45 / Chapter 2.9 --- Southern Blotting --- p.47 / Chapter 2.9.1 --- Transfer of DNA to membrane --- p.47 / Chapter 2.9.2 --- Preparation of probes --- p.47 / Chapter 2.9.3 --- Hybridization with radiolabeled probes --- p.48 / Chapter 2.10 --- Detection of HBeAg and HBsAg --- p.50 / Chapter 2.10.1 --- HBsAg assays --- p.50 / Chapter 2.10.2 --- HBeAg assays --- p.51 / Chapter 2.11 --- SEAP Reporter Gene Assay --- p.52 / Chapter 3 --- Results / Chapter 3.1 --- Templates Selected --- p.53 / Chapter 3.2 --- Results of Luciferase Assays --- p.58 / Chapter 3.2.1. --- BCP mutation of genotype A as control --- p.58 / Chapter 3.2.2. --- Effect of C1165T mutation on Xpro/enhI activity of HBV genotype B --- p.60 / Chapter 3.2.3. --- Effect ofT2712C mutation on pre-S1 promoter activity of HBV Genotype B --- p.60 / Chapter 3.2.4. --- Effect of G1613A mutation on core pro/enhII activity of HBV Genotype Cs --- p.64 / Chapter 3.2.5. --- G1613A and BCP mutation --- p.67 / Chapter 3.3 --- Full-length HBV Genome Clones --- p.70 / Chapter 3.3.1. --- Construction of replication-competent full-length HBV genome clones --- p.70 / Chapter 3.3.2. --- Drawbacks of the system --- p.78 / Chapter 3.4 --- Construction of a Replication-competent 1.3-fold HBV Clone --- p.82 / Chapter 3.4.1. --- Construction of the HBV (nt 979-2617) clone --- p.82 / Chapter 3.4.2. --- Construction of the HBV (nt 905-2000) clone --- p.86 / Chapter 3.4.3. --- Construction of 1.3-fold genotype Cs HB V clone --- p.89 / Chapter 3.4.4. --- Test for replication competency --- p.92 / Chapter 4 --- Discussion / Chapter 4.1 --- BCP Mutation as Control of the Luciferase Assay --- p.94 / Chapter 4.2 --- Promoter Activities Not Altered by T2712C and C1165T --- p.96 / Chapter 4.3 --- Mutation G1613A of Core pro/enhll --- p.98 / Chapter 4.3.1 --- Mutation resides in negative regulatory element of core promoter --- p.98 / Chapter 4.3.2 --- NRE and NRE-binding protein --- p.98 / Chapter 4.3.3 --- Relationship with BCP mutation --- p.101 / Chapter 4.4 --- HBV Constructs --- p.103 / Chapter 4.4.1 --- Rationale in re-construction of 1.3-fold HB V clone --- p.103 / Chapter 4.4.2 --- Replication competency --- p.104 / Chapter 4.5 --- Conclusion --- p.106 / Chapter 4.6 --- Future Work --- p.107 / Appendix --- p.108 / References --- p.140

Li, Sai Kam. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 162-179). / Abstracts in English and Chinese. / Abstract --- p.i / Abstract in Chinese (摘要） --- p.ii / Acknowledgements --- p.iii / Table of Content --- p.iv / Abbreviations --- p.xi / List of Figures --- p.xiv / List of Tables --- p.xvii / Chapter CHAPTER 1 --- INTRODUCTION / Chapter 1.1 --- Hepatitis B Virus / Chapter 1.1.1 --- General information --- p.1 / Chapter 1.1.2 --- Classification --- p.2 / Chapter 1.1.3 --- Virus life cycle and genome --- p.3 / Chapter 1.1.4 --- Hepatitis B virus X protein (HBx) --- p.7 / Chapter 1.2 --- Enigmatic functions of HB --- p.x / Chapter 1.2.1 --- HBx as a transactivator --- p.10 / Chapter 1.2.2 --- HBx as a cell cycle regulator --- p.12 / Chapter 1.2.3 --- HBx as an apoptosis modulator --- p.13 / Chapter 1.3 --- Etiology of HBV-mediated hepatocarcinogenesis --- p.14 / Chapter 1.4 --- Clinical mutants of HBV --- p.16 / Chapter 1.5 --- Hypothesis and aims of the research --- p.16 / Chapter 1.6 --- Basis of Tet-On system --- p.18 / Chapter CHPATER 2 --- EXPERIMENT MATERIALS / Chapter 2.1 --- Cell culture / Chapter 2.1.1 --- Cell-lines --- p.21 / Chapter 2.1.2 --- Culture medium --- p.22 / Chapter 2.1.3 --- Culture medium supplements --- p.23 / Chapter 2.2 --- Reagents for subcloning / Chapter 2.2.1 --- Reagents for polymerase chain reaction (PCR) --- p.24 / Chapter 2.2.2 --- Reagents for restriction enzyme digestion --- p.24 / Chapter 2.2.3 --- Reagents for ligation --- p.25 / Chapter 2.2.4 --- Reagents for electrophoresis --- p.25 / Chapter 2.2.5 --- Reagents for E. coli DH5a preparation --- p.25 / Chapter 2.2.6 --- Materials for bacterial culture work --- p.27 / Chapter 2.3 --- Reagents for subcellular localization study / Chapter 2.3.1 --- Reagents for cell staining --- p.28 / Chapter 2.3.2 --- Reagents for mounting slides --- p.29 / Chapter 2.3.3 --- Materials for site-directed mutagenesis --- p.29 / Chapter 2.4 --- Reagents for cell cycle analysis and cellular proliferation / Chapter 2.4.1 --- Reagents for cell cycle analysis --- p.29 / Chapter 2.4.2 --- Reagents for cellular proliferation study --- p.30 / Chapter 2.5 --- Reagents for protein expression study / Chapter 2.5.1 --- Cell lysis buffer --- p.30 / Chapter 2.5.2 --- Reagents for SDS-PAGE --- p.30 / Chapter 2.5.3 --- Reagents for Western blot --- p.33 / Chapter 2.5.4 --- Antibodies --- p.34 / Chapter 2.6 --- Reagents for gene expression study / Chapter 2.6.1 --- Reagents for RNA extraction --- p.36 / Chapter 2.6.2 --- Reagents for first strand cDNA synthesis --- p.37 / Chapter 2.6.3 --- Reagents for real-time PCR --- p.37 / Chapter 2.7 --- Reagents for establishment of Tet-On inducible stable cell-lines / Chapter 2.7.1 --- Reagents for MTT assay --- p.38 / Chapter 2.7.2 --- Reagents for selection of stable clones --- p.38 / Chapter 2.8 --- Vectors used in the project / Chapter 2.8.1 --- Vectors for subcellular localization study --- p.39 / Chapter 2.8.2 --- Vectors for establishment of Tet-on inducible cell-lines --- p.39 / Chapter 2.9 --- Primers used in the project / Chapter 2.9.1 --- Primers used for subcloning --- p.42 / Chapter 2.9.2 --- Primers used for site-directed mutagenesis --- p.43 / Chapter 2.9.3 --- Primers used in real-time chain polymerase reaction --- p.43 / Chapter CHAPTER 3 --- RESEARCH METHODS / Chapter 3.1 --- Subcloning of HBx and mutant genes into a green fluorescence protein (GFP) expression vector / Chapter 3.1.1 --- Amplification of HBxWt，HBxΔC44 and HBxAN60 genes --- p.45 / Chapter 3.1.2 --- Purification of PCR products --- p.46 / Chapter 3.1.3 --- Restriction enzyme digestion --- p.47 / Chapter 3.1.4 --- Ligation of gene products with pEGFP-C 1 vector --- p.47 / Chapter 3.1.5 --- Preparation of chemically competent bacterial cells E. coli strain DH5α --- p.47 / Chapter 3.1.6 --- Transformation of the ligation product into competent cells --- p.48 / Chapter 3.1.7 --- PCR confirmation of successful ligation --- p.48 / Chapter 3.1.8 --- Small scale preparation of bacterial plasmid DNA --- p.49 / Chapter 3.1.9 --- DNA sequencing of the cloned plasmid DNA --- p.50 / Chapter 3.1.10 --- Large scale preparation of target recombinant plasmid DNA --- p.50 / Chapter 3.2 --- Subcellular localization pattern study / Chapter 3.2.1 --- Cell transfection --- p.51 / Chapter 3.2.2 --- Mitochondria and nucleus staining --- p.52 / Chapter 3.2.3 --- Epi-fluorescence microscopy --- p.53 / Chapter 3.2.4 --- Analysis of fluorescence images --- p.53 / Chapter 3.2.5 --- In vitro site-directed mutagenesis --- p.53 / Chapter 3.3 --- Cell cycle phase analysis with flow cytometry / Chapter 3.3.1 --- Cell transfection --- p.55 / Chapter 3.3.2 --- Cell staining --- p.55 / Chapter 3.3.3 --- Flow cytometry --- p.55 / Chapter 3.4 --- Cellular proliferation quantification by BrdU proliferation assay / Chapter 3.4.1 --- Cell transfection --- p.57 / Chapter 3.4.2 --- BrdU ELISA measurement --- p.57 / Chapter 3.5 --- Protein expression / Chapter 3.5.1 --- Cell lysate collection --- p.58 / Chapter 3.5.2 --- Quantification of protein samples --- p.59 / Chapter 3.5.3 --- SDS-PAGE --- p.59 / Chapter 3.5.4 --- Western blot --- p.60 / Chapter 3.5.5 --- Western blot luminal detection --- p.60 / Chapter 3.6 --- Gene expression / Chapter 3.6.1 --- Primer design --- p.61 / Chapter 3.6.2 --- Cell transfection --- p.61 / Chapter 3.6.3 --- RNA extraction --- p.61 / Chapter 3.6.4 --- Reverse transcription for first strand complementary DNA (cDNA) --- p.63 / Chapter 3.6.5 --- Quantitative real-time PCR --- p.63 / Chapter 3.7 --- Establishment of Tet-On inducible stable cell-lines / Chapter 3.7.1 --- Subcloning of HBx gene into pTRE2 vector --- p.64 / Chapter 3.7.2 --- Construction of WRL68/Tet-On stable cell-lines --- p.64 / Chapter 3.7.3 --- Construction of WRL68/Tet-On HBx and mutants expression cell-lines --- p.68 / Chapter 3.7.4 --- Characterization of Tet-On gene expression monoclones --- p.69 / Chapter 3.8 --- Statistical analyses --- p.70 / Chapter CHPATER 4 --- STUDY ON MITOCHONDRIA TARGETING / Chapter 4.1 --- Establishment of pEGFP-Cl-HBx and mutants constructs --- p.71 / Chapter 4.2 --- Transactivation C-terminus domain is essential for granular localization --- p.73 / Chapter 4.3 --- Wild-type HBx localizes in mitochondria --- p.76 / Chapter 4.4 --- C-terminal transactivation domain is sufficient for mitochondria targeting --- p.79 / Chapter 4.5 --- Mapping of the HBx region crucial for mitochondria targeting --- p.81 / Chapter 4.6 --- The 111-117 amino acids in HBx do not work as a signal peptide --- p.83 / Chapter 4.7 --- Site-directed mutagenesis identifies the key amino acid at 115 in HBx for mitochondrial targeting --- p.85 / Chapter CHAPTER 5 --- CELL PROLIFERATION AND REGULATION / Chapter 5.1 --- Alteration of S-phase distribution in cell cycle --- p.88 / Chapter 5.2 --- Analysis of DNA synthesis using BrdU proliferation ELISA --- p.92 / Chapter 5.3 --- Differential molecular regulation of cell cycle --- p.94 / Chapter 5.4 --- Regulation of the mRNA expression levels of cyclin-dependent kinases inhibitors p2raf/cipl and p27kipl --- p.98 / Chapter CHAPTER 6 --- TRANSACTIVATION AND RAS/RAF/MAPK PHOSPHORYLATION / Chapter 6.1 --- Determination of p53-dependency of p21、vaf/cipl expression --- p.101 / Chapter 6.2 --- Ras/Raf/MAPK pathway activation by HBx variants / Chapter 6.2.1 --- ERK1/2 phophorylation by HBx variants --- p.104 / Chapter 6.2.2 --- ERK inhibition blocks the regulation effect on p53Wt and p21waf/cipl --- p.107 / Chapter 6.3 --- Transactivation activity on oncogenes/ proto-oncogenes / Chapter 6.3.1 --- Effect on c-myc (NM´ؤ002467) mRNA expression --- p.109 / Chapter 6.3.2 --- Effect on RhoC (NM_017744) and Rabl4 (NM´ؤ016322) mRNA expression --- p.112 / Chapter CHAPTER 7 --- CONSTRUCTION OF TET-ON INDUCIBLE CELL-LINES / Chapter 7.1 --- Establishment of WRL/Tet-On monoclonal cell-lines Page / Chapter 7.1.1 --- Determination of geneticin selection dosage --- p.116 / Chapter 7.1.2 --- Selection of the best WRL/TOn clone using luciferase assay --- p.118 / Chapter 7.2 --- Establishment of inducible WRL/TOn/Gene monoclonal cell-lines / Chapter 7.2.1 --- Determination of hygromycin selection dosage --- p.120 / Chapter 7.2.2 --- Selection of positive WRL/TOn/Gene clones with viral genes --- p.122 / Chapter 7.3 --- Characterization of TOXDC1 cell-line / Chapter 7.3.1 --- Cell morphology --- p.125 / Chapter 7.3.2 --- Growth pattern of TOXDC1 --- p.126 / Chapter 7.3.3 --- HBxAC44 induced p21waf/cipl mRNA expression --- p.127 / Chapter 7.3.4 --- Doxycycline concentration dependent HBxAC44 expression in TOXDC1 --- p.129 / Chapter CHAPTER 8 --- DISCUSSION / Chapter 8.1 --- Selection of cell model / Chapter 8.1.1 --- Selection of cell models --- p.130 / Chapter 8.1.2 --- Selection of truncation mutant --- p.131 / Chapter 8.2 --- Differential sub-cellular localization of HBx and its variants / Chapter 8.2.1 --- Mechanisms of mitochondria targeting --- p.132 / Chapter 8.2.2 --- Mitochondria as site of HBx-induced apoptosis --- p.134 / Chapter 8.2.3 --- Stimulation of calcium release from mitochondria by wild-type HBx --- p.135 / Chapter 8.3 --- Cell cycle distribution profiling and its regulations / Chapter 8.3.1 --- Cell cycle pattern and cell proliferation --- p.136 / Chapter 8.3.2 --- Differential cell cycle molecular pathway activation --- p.138 / Chapter 8.4 --- Ras/Raf/MAPK mediated transactivation by HBxWt and its mutants / Chapter 8.4.1 --- p53-mediated p21waf/cipl expression --- p.142 / Chapter 8.4.2 --- ERK-mediated p21waf/cipl and wild-type p53 mRNA expression --- p.143 / Chapter 8.4.3 --- Regulation of oncogenes/ proto-oncogenes expression --- p.147 / Chapter 8.5 --- General discussions on differential effects of HBxWt and HBxAC44 --- p.149 / Chapter 8.6 --- Establishment of Tet-On/HBxAC44 cell-line TOXDC1 --- p.153 / Chapter 8.7 --- Conclusions --- p.154 / Chapter 8.8 --- Future Prospects / Chapter 8.8.1 --- From mitochondria targeting to calcium signaling --- p.157 / Chapter 8.8.2 --- Construction of a complete cell cycle regulation pathway --- p.158 / Chapter 8.8.3 --- Elucidation of the transcriptional transactivation regulation --- p.159 / Chapter 8.8.4 --- To make the best use of the Tet-on stable cell-line TOXDC1 --- p.159 / Chapter 8.8.5 --- Study with other carboxy-terminal truncation mutants --- p.160 / Chapter 8.8.6 --- In vivo study --- p.160 / REFERENCES --- p.162

Leung, Chung Yan. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (leaves 100-113). / Abstracts in English and Chinese. / Abstract --- p.I / 摘要 --- p.III / Acknowledgements --- p.V / List of figures --- p.VI / List of tables --- p.VIII / Abbreviations --- p.IX / Table of Contents --- p.XII / Chapter Chapter 1: --- Introduction / Chapter 1.1 --- Epidemiology of hepatocellular carcinoma (HCC) --- p.1 / Chapter 1.2 --- Etiology of heptocellular carcinoma (HCC) --- p.1 / Chapter 1.3 --- HBV genome structure --- p.2 / Chapter 1.4 --- HBV pathogenesis --- p.2 / Chapter 1.5 --- Hepatitis B virus X protein (HBx) --- p.3 / Chapter 1.6 --- Oxidative stress and antioxidant --- p.5 / Chapter 1.6.1 --- Glutathione (GSH) --- p.5 / Chapter 1.6.2 --- Superoxide dismutase (SOD) --- p.7 / Chapter 1.6.3 --- Oxidative stress in HBV-related liver disease and HCC --- p.8 / Chapter 1.7 --- Apoptosis and necrosis --- p.9 / Chapter 1.7.1 --- Apoptotic pathways --- p.9 / Chapter 1.8 --- Role of HBx in apoptosis --- p.10 / Chapter 1.9 --- Transcriptional activity by HBx --- p.12 / Chapter 1.10 --- Chemotherapy drug resistance --- p.13 / Chapter 1.11 --- Objectives of study --- p.14 / Chapter Chapter 2: --- Methods and materials / Chapter 2.1 --- Construction of plasmid --- p.23 / Chapter 2.1.1 --- PCR amplification of wild-type and mutant HBx --- p.23 / Chapter 2.1.2 --- Agarose gel extraction --- p.25 / Chapter 2.1.3 --- Restriction enzyme digestion --- p.26 / Chapter 2.1.4 --- Ligation of vectors and gene of interest --- p.26 / Chapter 2.1.5 --- Preparation of competent cells for transformation --- p.27 / Chapter 2.1.6 --- Transformation of plasmid in competent cells --- p.27 / Chapter 2.1.7 --- Plasmid extraction by mini-prep --- p.28 / Chapter 2.1.8 --- DNA sequencing of the inserted genes --- p.29 / Chapter 2.2 --- Transfection --- p.30 / Chapter 2.2.1 --- Cell line --- p.30 / Chapter 2.2.2 --- Lipofectamine transfection --- p.31 / Chapter 2.2.3 --- Construction of stably-transfected cell lines --- p.31 / Chapter 2.3 --- Detection of expression of transfected gene in mRNA level by RT-PCR --- p.32 / Chapter 2.3.1 --- RNA extraction --- p.32 / Chapter 2.3.2 --- Reverse transcription-polymerase chain reaction (RT-PCR) --- p.33 / Chapter 2.3.3 --- Agarose gel electrophoresis --- p.36 / Chapter 2.4 --- Detection of expression of transfected gene in protein level by Western blot --- p.36 / Chapter 2.4.1 --- Sample preparation --- p.36 / Chapter 2.4.2 --- Measurement of protein concentration --- p.36 / Chapter 2.4.3 --- Sodium dodecyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE) --- p.37 / Chapter 2.4.4 --- Transfer of proteins to nitrocellulose membrane --- p.38 / Chapter 2.4.5 --- Immunoblotting of protein --- p.38 / Chapter 2.5 --- Measurement of reduced glutathione (GSH) concentration in cell lines --- p.39 / Chapter 2.5.1 --- Sample preparation --- p.39 / Chapter 2.5.2 --- Measurement of GSH concentration --- p.39 / Chapter 2.6 --- Superoxide dismutase (SOD) activity in cell lines --- p.40 / Chapter 2.6.1 --- Sample preparation --- p.40 / Chapter 2.6.2 --- Measurement of total SOD activity --- p.41 / Chapter 2.6.3 --- Measurement of Cu/ZnSOD and MnSOD by Western blot --- p.42 / Chapter 2.7 --- Cell proliferation assay --- p.43 / Chapter 2.7.1 --- Drugs and concentration --- p.43 / Chapter 2.7.2 --- "MTT(3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide)assay" --- p.43 / Chapter 2.7.3 --- Cell proliferation and cytotoxicity of the drugs --- p.44 / Chapter 2.8 --- Detection of apoptosis by flow-cytometry --- p.44 / Chapter 2.8.1 --- Cell culture --- p.44 / Chapter 2.8.2 --- Cell fixation --- p.45 / Chapter 2.8.3 --- Cell staining --- p.45 / Chapter 2.8.4 --- Flow cytometry analysis --- p.46 / Chapter 2.9 --- Detection of protein involved in apoptotic pathway --- p.46 / Chapter 2.9.1 --- Antibodies --- p.46 / Chapter 2.9.2 --- Sample Preparation --- p.47 / Chapter 2.9.3 --- Measurement of protein concentration --- p.48 / Chapter 2.9.4 --- Western blotting --- p.49 / Chapter Chapter 3: --- Establishment of HBx transfected stable cell lines / Chapter 3.1 --- Introduction --- p.55 / Chapter 3.2 --- Results --- p.56 / Chapter 3.2.1 --- Plasmid construction --- p.56 / Chapter 3.2.2 --- Stable transfection of cell lines --- p.57 / Chapter 3.2.3 --- Morphology of wild type and mutant HBx-transfected cell lines --- p.58 / Chapter 3.3 --- Discussion --- p.58 / Chapter Chapter 4: --- Antioxidant level in HBx transfected cell lines / Chapter 4.1 --- Introduction --- p.68 / Chapter 4.2 --- Results --- p.70 / Chapter 4.2.1 --- Glutathione (GSH) concentration in different cell lines --- p.70 / Chapter 4.2.2 --- Superoxide dismutase (SOD) activity in different cell lines --- p.71 / Chapter 4.2.2.1 --- Total SOD activity --- p.71 / Chapter 4.2.2.2 --- Cu/ZnSOD --- p.71 / Chapter 4.2.2.3 --- MnSOD --- p.72 / Chapter 4.3 --- Discussion --- p.72 / Chapter Chapter 5: --- Involvement of HBx in apoptotic pathway / Chapter 5.1 --- Introduction --- p.81 / Chapter 5.2 --- Results --- p.82 / Chapter 5.2.1 --- Cell proliferation of HBx transfected cells --- p.82 / Chapter 5.2.2 --- Apoptosis of HBx transfected cells --- p.83 / Chapter 5.2.3 --- Cytotoxicity of fluorouracil (5FU) and doxorubicin (DOX) in HBx transfected cells --- p.84 / Chapter 5.2.4 --- Detection of anti-apoptotic proteins cIAP2 and Bcl-2 in HBx-transient and stably transfected cells --- p.84 / Chapter 5.3 --- Discussion --- p.85 / Chapter Chapter 6: --- Concluding remarks and general discussion / Chapter 6.1 --- General discussion --- p.93 / Chapter 6.2 --- Future work --- p.97 / Chapter 6.3 --- Summary --- p.99 / References --- p.100 / Appendix 1 --- p.114